Optimizing Parameters for Copper and Aluminum

The article provides parameter optimization solutions and practical techniques for the common problems encountered in laser marking on highly reflective materials such as copper and aluminum.It provides a detailed explanation of how to improve the clarity and efficiency of laser marking, including the power, frequency and speed of the laser, and is intended for reference by operators in the fields of industrial processing and electronics.

Why do the markings on aluminum and copper coins tend to wear off?

Copper and aluminum have a high surface reflectivity, so using normal laser parameters to mark the material often results in a "burn-through" or a fuzzy image.In particular, with thin materials, if the power is increased even slightly, it may go right through.We discovered that we had to find a balance point between two factors: the characteristics of the materials and the parameters of the equipment.

Selecting equipment and laying a foundation.

Fiber lasers are first choice.

Compared to CO2 lasers, the 1064-nanometer wavelength of fiber lasers is better suited for metal materials.If conditions permit, it is better to use a device with a red light to indicate the position, so that it is not necessary to repeatedly adjust the position.

Basic parameters.

As an example, for a 30W fiber laser, the power should be set at 15 % (don't start at 100 %) and the frequency at 20-50kHz, with the speed set at 800-1200mm / s.This combination avoids excessive charring and ensures that the lines are continuous.

Parameter optimization techniques.

First, do a small test.

Cut a 5x5 cm test area out of the material, and engrave it with different combinations of parameters (for example, 10/15/20 % power and three speeds).When comparing the effects, pay attention to two points: whether the light-colored oxidized layer is even, and whether there are any rough edges.

The "cooling secret" of aluminum marking.

Aluminum is a good conductor of heat, but it also easily oxidizes, which can lead to instability of the oxide layer.A little trick: Put a ring of high temperature tape around the target area. This will reduce the interference from the reflected light and provide localized insulation.Once the tape is removed, the contrast of the pattern is increased by about 30 %.

A solution for preventing copper from sticking to the stamp.

Copper can easily produce slag at high temperatures, so it is best to wipe the surface with an alcohol-soaked cloth before marking, and then apply a thin layer of a special marking agent for metals.After this treatment, the slag will attach to the coating, and the pattern will be clean after the part is rinsed.

Common problems and emergency procedures.

What do you do if the pattern is blurry?

First check to see if the focal length is off, then use a "low-power, multi-pass" method to make repairs.For example, by reducing the power to 8 % and marking the same area two or three times, you can get a finer effect than with a single high-power marking.

What do you do if the material is penetrated?

If thin sheets (less than 0.5 mm) are being perforated, it may be that the frequency is too low, and the energy is being piled up.The frequency was raised to 80 kHz, the speed to 1500 mm / s, and a rotating worktable was used to disperse the heat quickly.

Finally, it should be noted that the actual output power of various brands of equipment can vary, and the parameters in this article should be adjusted according to the user's own machine.Every time you change materials, be sure to keep the test records. In this way you can gradually build up your own database.